Method of and apparatus for projecting röntgen images.



G. BUCKY.

METHOD OF AND APPARATUS FOR PROJECTING RONTGEN IMAGES.

APPLICATION FILED FEB- 3, 1914- I Patented Dec. 21, 1915.

3 SHEETSSHEET I.

G.BUCKY. METHOD OF AND APPARATUS FOR PROJECTING RONTGEN IMAGES.

APPLICATION FILED FEB13, l9l4- I 1,164,987. Patented Dec.21,1915.

3SHEETS-SHEET 2.

G. BUCKY-,

METHOD-0F AND APPARATUS FOR PROJECTING RONTGEN IMAGES.

APPLICATION FILED FEB 3, 1914.

1,164,987, Patented Dec. 21, 1915.

3 SHEETS-SHEET 31 for Projecting GUSTAV BUCKY, OF BERLIN,

GERMANY, ASSIGNOR TO SIEMENS 8t HALS KE, BERLIN, GERMANY, A CORPORATION OF GERMANY.

n. c., or

METHOD OF AND APPARATUS FOR PROJECTING RGNTGEN IMAGES.

To all whom it may concern:

Be it known that I, GUSTAV BUGKY, a German citizen, and resident of Berlin, Germany, have invented certain new and useful Improvements in Methods of and Apparatus Rontgen Images, of which the following is a specification.

In the practice of Rontgenography and Rontgenoscopy, as known, it has been found that a veiling of the image resulting into a foggy appearance of the picture is due to the secondary Rontgen rays which are generated when the primary Rontgen rays pass through a body.

It is the object of my invention to devise an apparatus which prevents the in urio11s efiect of these secondary rays upon the Rontgen image'on a photographic plate as well as on a fluorescent screen in a very perfect manner and so that it'will yet be possible to obtain the entire picture by a single photographic process.

According to this invention between the plate carrying the Rontgenimage and the body a grid or screen is provided which is composed of several chambers or ducts not unlike to the structure of a honeycomb. These ducts or chambers are made of a material which is little permeable for rays and the walls of these chambers are preferably so arranged that they will be positioned in the direction of the primary rays, so that they will not obstruct the passage of the same. The arrangement of the chambers in said grid will enable one to obtain a most effective protection ondary rays which are generated in the body, for these injurious rays will be prevented from arriving at the carrier of the image the greater the depth of the several chambers is and the smaller their crosssection. This condition can be fulfilled only if the walls of said chambers are parallel to the direction of the rays.

The screen or grid can be of plane or spherical form.

. image of the grid which may sometimes be undesirable, especially in case a photograph be taken, the grid may be movably mounted and may be provided with a contrivance for imparting motion to the same. This motion should be rather quick and may Specification of Letters Patent.

general arrangement comprising a tube, a body to be photographed and the graphic plate,

Rontgen from sec-.

to be taken on a photographic a fluorescent screen arranged Inorder not to obtain an Patented Dec. 21, 1915.

Application filed February 3, 1914. Serial No. 816,137.

either be a linear, tical-or any similar motion, so that shadows which are cast by the grid'will not have any influence upon the image. Furthermore deoscillating, circular, ellipvices are preferably employed which permit an accurate adjustment of the Rontgen tube above the center of the grid and in a distance corresponding to the inclination of the walls, of the chambers therein.

My invention will be more fully understood by reference to the accompanying drawings, of which- Figure ontgen means for preventing secondary Rontgen rays or glass rays to pass to the photo- Fig. 2 a grid which is a preferable form of the aforementioned means of Fig. 1, Figs. 3 and 4 a view and cross-section respectively of a grid according to Fig. 2 having the form of a spherical calotte, Fig. 5 showing agrid whose carrier may be removed by dissolving the same, for instance in a liquid, Figs. 6 and 7 are a side view and plan view respectively of an apparatus for securing the centering of the Rontgen tube with respect to the direction of the walls of the chambers of the grid. Figs. 8 and 9 are a side view and a plan view respectively for centering the grid, and Figs. 10

Ron-tgen tube above the and 11 are a top and side a motion to the grid for rendering noninjurious the effect of the shadows walls thereof.

In Fig. 1, 1 represents the Rontgen tube, 2 the body from which an image is desired plate 3 or on at this place instead of a plate. Between the body and the plate a grid 4 is provided, said grid having chambers whose walls are positioned to coincide in direction with that of the primary Rontgen rays, so that the prolongations of the walls of said chambers will all intersect at the anticathode 5 of the Rontgen tube. In Fig. 2 the grid with its chambers is shown in a plan view representing the exact form of the chambers or ducts-of said grid. This figure shows three modifications of the 1 is a diagrammatic view of the of a further arrangement of the Walls forming the ducts or chambers of the connecting bridges,

grid or screen. In the upper part of Fig. 2 there are shown parallel and unidirectional as indicated in the drawing. From the three forms of the grid or screen represented in ig. 2 I regard that shown in the middle part of this figure as the most advantageous form of the ducts or chambers of the grid.

. rangementshownin Fig.

body I.

In order to illustrate the action of the grid, two points 32, and 22 are assumed to be the points of issue of secondary rays,- said points being near to the underside of the from which a Rontgen photograph shallbe taken. In case of sufi'icient depth and. suliiciently small'cross-section of the chambers only those secondary rays issuing from p, and 32 will arrive upon the plate 3' which ave approximately the same direction as the primary Rontgen rays, while the remaining secondary rays will be absorbed he walls of the chambers of the grid. T erefore essentially only evenly directed rays will serve to generate an image and therewith the veiling or fogging of the latter will be avoided. v

For taking photographic Rontgen pictures it is advantageous to build the grid lIitO the case surrounding the photographic p ate.

Besides the grid serving-for obstructing; the rays issuing from thebody in the ar- -1 a likegrid 6 is -provided in order to render non-injurious and a cross-section wall of the Gntgen tube, rays.

body to be other hand th radially directed walls of said grid will be facilitated. The width-of the secondary rays issuing from the glass the so-called glass The walls forming the several chambers of this grid are likewise so directed that they will coincide with the direction of the primary rays in order to permit the passage of the latter. a

In Figs. 3 and 4 a grid is shown in a view respectively, said grid having the orm of a spherical calotte. This form of grid on the one hand has the advantage that it will eventually better fit the photographed and that on the e manufacture of exactly the chambers of or the width or themeshes of the chambers be made as narrow as deslred said grid may and the grid itself accordingly become of a .A grid of this kind very small thickness. may for instance be manufactured in such a manner that, as apparent from Fig. 4-, a form of the grid with parallel walls is cut center of the spherical calotte the walls of the grid will exactly coincide with the direction of the primary Rontgen radiation. As a filling material for the cuts or-chambers of This form of the grid has the advantagethat by reason of the coherent celluloid plate the lead grid may be made very thi so that it will accordingly cast only little shadow upon the plate.

If the filling material is pressed under sufficient pressure into the cut spaces, a thin coherent grid will, be plate in which the grid form is cut terial' is chosen which easily removed, for instance, a material which is soluble in certain liquids, according to th also a coherent grid can a maplate' carrying given spherical shape by pressing the same into a proper form, andafter said plate has assumed spherical shape it may further be finished or worked upon its surface by planing or asimilar mechanical operation in such limiting surfaces will be made'thereon. For this purpose the thickness of the plate when being in spherical form must be rather considerable in order to obtain a sufficient thickness of the plate after the aforementioned plane limiting surfaces have been-made thereon. Another way of making the spherical grid orscreen according to my invention consists therein that a grid form with parallel walls is first cut into a plate. Thereupon the grid is filled with a material which is sene and the 1 obtained. If for a' into a plate 6 which plate is made from a perferably the property of I emanating few secondary rays, such as' for afterward may be '100 made without having .a speclal carrier.

80 having the anticathodes positioned in the I .grid must arrangement A process for making plane grids consists therein that first the grid with its carrier is made in the form of a calotte, whereupon either side is worked by a planer or the like. In this case the grid Walls. themselves must form a firm unit or they must be Well joined with the carrier by means of putty or the like. Fig. 5 shows in a cross-section a grid of this kind whose carrier may also be removed by dissolution or the like.

In Fig. 6 I have shown an example of an arrangement for obtaining a centered position of the Riintg'en tube relatively to the walls of the grid. The Rontgen tube 1 hereby is mountedin a holder 8 which is fixed on a U-shaped frame 9. This frame may be fixed on a table or tripod by means of a pivot 10 and also carries a holding device 11 permitting to receive the grid 4 and eventually also the photographic plate 3 in such a place that the anticathode of the Rontgen'tubewill be exactly positioned at the point of intersection of the planes of all walls of the grid. This arrangement can be advantageously used in case stereoscopic picturesare desired, in case of which with the displacement of the vRontgen tube also the be shifted. In thiscase only a shifting of the-frame 9 will be required.

In Figs. 8 and 9 I have shown a further of centering the Rontgen tube above the grid. Hereby it is assumed that the proper distance of the tube from the grid is secured in another way by proper arrangemen-tsa Thereby at the frame 11 carrying the grid- 4 a trestle 12 is provided carry- I ing at its-,upper end an iron tube 14 which is rotatable around a journal 13. A stop 15 limits the motion of this arm in the one direction and more particularly as soon as this arm will be ositioned exactlv above the center plane of the grid 4. The arm 14' is equipped with an extension 16 telescoping therewith, and carries a sighting device which consists of .a tube 17 within which there are spider threads 18. At its under end the tube 17 is provided with an extension 19 fitting said tube, which extension contains a mirror 20 inclined at an angle of 45. As indicated by the dotted lines representing the direction of rays issuing from the eye 21, by means of the mirror .20 and the spider threads 18 it may be exactly ascertained whether the anticathode 5 of the Rontgen tube 1 be positioned exactly perpendicular above the center of the grid 4. After proper adjustment of the Rontgen tube, for thephotographic exposure, the

sighting device with the arm 14 is swung out of the actuating .range of the. grid in the direction as indicated by the arrow.

The trestle 12- is fixed by v journals 22' fitting into sleeves at the frame 11 of the grid. The sighting device accordingly may vided with images,

plate immediately upon the latter,

be fixed at the long or narrow side of the grid, whereby the corresponding length of theswinging arm can ing its part 16 relatively to the part 14 and fixing the position by means of a screw.

For imparting motion, as above pointed out, to the grid 4, the frame 11- thereof is protwo extensions 25 having circular recesses, in which disks 2 6 are rotatably mounted which disks are eccentrically fixed upon axles 27. These axles are coupled by means of conical gears 28 with a third axle 29 which latter may be rotated by means of a crank 30. Upon rotation of 'said crank through the eccentrical disks a motion will be imparted to the extensions 25 and therewith to the entire grid 4, so that each point of said grid will describe a circular path. The eccentricity of the disks thereby is chosen, so that the diameter of the circle of motion, which for instance is indicated at the point p at Fig. 10, will be just equal to the length of the side of the smallest squares of the grid.

The velocity of the drive must be such that the walls of the grid will not cast a visible shadow upon the photographic plate or upon the fluorescent screen. For'this purpose it is only required to rotate the crank 30 at the proper speed. Instead of 1. An apparatus for projecting Rontgen images, comprising source and said plate immediately upon the latter, said grid or screen being composed of a number of chambers having walls of a form to obstruct passage of secondary Rontgen rays. j

2. An apparatus for projecting Rontgen comprising a source of Rontgen rays, a plate carrying the Riintgen image, and .a grid or screen made of a material which is little absorbing Rontgen rays and emanating only few secondary rays which and said said grid or screen having a plurality of chambers with walls in the'direction of the rays originating from said source.

is arranged between said source 3. In combination with a Rontgen apparatus, a grid or screen composed of several a source of Rontgenrays, a plate carrying the Itontgen image and a grid or screen interposed between said and means for tively to said grid chambers for screening be the secondary Rontgen rays, said grid or screen havin partitions with walls directed toward the anticathode of-the Rontgen tube.

4. In combination with'a Rontgen apparatus, a grid or screen of the-form of a spherical calotte for screening ofl" secondary Routgen rays, said grid or screen having a number of partitions with walls of a direction to intersect at the anticathode of the Rontgen ratus, a source of Rontgen rays,a plate carrying the Rontgen image, and two grids or screens interposed between said source and said plate, immediately near to said source,

one of which is positioned each of said grids or ys'creensbeingcomposed of a number of par titions with walls which are "evenly directed with the Rontgen source... I 1

8. In combination with a Rontgen apparatus, a grid or screen having partitions with wallslessentially positioned in the direction of the primary Rontgen rays and means for moving said grid or screen so as to prevent a visible shadow of said grid or screen on rays issuing from said the image.

9. In combination with a Rontgen apparatus, a grid or screen having partitions with walls essentially positioned in the direction of the primary Rontgen rays, and means for imparting a motion to said grid or screen,

said motion having in every direction a maximum amplitude not surpassing that of the width of the meshes of said grid or 10. A grid or screen for Riintgen apparatus, having the shape of a spherical calotte with partitions having radially directed walls for being inserted into the path of f Rontgen rays to have the intersecting point.

of said walls coinciding with the source of said Rontgen rays, said grid or screen consisting of a material which is little absorbing Rontgen rays and little emanating secondary rays, a filling for saidgrid or screen said filling consisting of a material which is impermeable for Rontgen rays. 7

11. The 'process of making a spherically shaped grid or screen having radially diwith parallel walls into a a material which is slightly absorbing said plateby upon said plate and the other rected partition walls for screening Rontgen rays, which consists in cutting a grid form plate made from Rontgen rays and slightly emanating secondary rays, filling said grid form with a material which is impermeable 'for Rentgen rays, and subsequently bending said plate into spherical shape.

12. The process of making a spherically shaped grid or screen having radially direetedpartition walls for screening Rontgen rays, which consists in cutting a grid form with parallel walls into a plate made 'from.

a material which is slightly absorbing Riintgen rays and slightly emanating secondary rays, filling said grid form with a material which is impermeable for Rontgen rays, subsequently bending said plate into spherical shape and separating said grid from dissolving the same in aliquid.

13. The process of making a spherically shaped grid or screen having radially directed partition walls for screening Rontgen rays, which consists in cutting a grid form with parallel walls into a plate made from a material which is slightly absorbing Rontgen rays and slightly emanating secondary rays, filling said grid form with a material which is impermeable for Rfintgen' rays, subsequently bending said aplate into spherical shape and finishing the said spherically shaped grid or screen so as to be limited by plane surfaces.

14. The process of making a spherically shaped grid or screen having radially directed partition walls for screening Rontgen .rays, which consists in cutting a grid form with parallel walls into a plate made from a material which is slightly absorbing Riintgen rays and slightly emanating secondary rays, filling said grid form with a material which is impermeable for Rontgen' rays, subsequently bending said plate into spherical shape, separating said grid from said plate by dissolving the same in a liquid and finishing the said spherically shaped grid or screen so as to .be limited by plane surfaces.

15. Apparatus for projecting Rontgen images, comprising a Rontgentube, a plate carrying the Rontgen image, a grid or v screen with partitions screening ofi" secondary Rontgen rays, said screen being ar- 'ranged between said source and said plate immediatety upon the latter, and a sighting device for centeringthe anticathode of said tube relatively to said grid or screen.

16. In combination with a Rontgen apparatus, consisting of a source of Rontgen rays and a plate carrying the Rontgen image, a grid or screen having partitions with walls essentially positioned in the direction of the primary Rontgen rays, said grid or sreen being arreng and said 'plate imme and means for keeping's in motion, so 'as to p 5 of said gri the image.

witne ed between said source In reven d or screen from being thrown on ss'yhereof I gave hereunte set I y signature in the presence of two subdiatelydupondthe latter, scribing witnesses.

a1 onscreen a t a g shadow GUSTAV BUCKY.

Witnesses:

WOLDEMAR HAUPT, HENRY HASPER. 

